The present invention relates to a method for selectively absorbing through the human skin the trace mineral cations, zinc(II), and copper (II), in a manner which does not alter the permeability of the human skin to ions in general, thus avoiding any resulting inflammatory reaction which occurs when the permeability of the human skin to ions in general is altered; and also in a manner which will leave the ions free inside the cells to act as enzyme activators, or function as electrophilic agents, for beneficial therapeutic use not being obtained by the administration of the corresponding trace minerals in oral or parenteral dosage form, and usual dosage range.
U.S. Pat. No. 3,923,982 teaches intramuscular and subcutanaceous injection of oil suspensions of copper, zinc and manganese compounds in herd animals to overcome trace element deficiency. The present invention on the other hand does not treat or prevent trace mineral deficiencies in humans but enables cations of zinc(II), and copper(II) to be transported across the membranes of the epidermis and dermis for a beneficial therapeutic use which is not obtained by administration of zinc, and copper compounds orally or parenterally in the usual dosage ranges.
Vashilinko et al., Farmatsiya, (Moscow), (1973), 22 (4), 26-30 teach that the drugs, sodium sulfacyl and potassium iodide, are released into the skin and blood more rapidly when prepared in an emulsion base containing sodium lauryl sulfate than when prepared in an emulsion base stabilized with lanolin. This refers to the complex action of surfactants in general on drug absorption and show how the absorption of drugs can be altered by the use of surfactants. But this only refers to drugs that are absorbed through the skin to a certain extent normally, and shows that this absorption can be increased by the use of surfactants. It does not show that the divalent cations zinc(II), and cooper(II), can be selectively absorbed through the skin without altering the permeability of the skin to ions in general, whereas this invention shows how this can be achieved, and it shows the exact mode of action of such a trace mineral cream.
Dugard et al., J Invest.Dermatol. (1973), 60 (5) 263-9, and Riker et al., Acta Fac. Med. Univ. Burn. (1972) 40 (Pt. 1) 177-80 both teach the skin permeability of ionic surfactants and their effects on the permeability of the human epidermis, and their significance for the absorption of certain ions. But both of these investigations were carried out, in vitro, to demonstrate the possible toxicological effects of surfactants. Dugard et al show that solutions of ionic surfactants (both anionic and cationic) increased the permeability of isolated epidermal membranes. But it is a well known fact that substances that increase the permeability of human skin to ions in general also cause skin damage and there is a distinct relationship between the damage caused to the skin and the increased permeability of human skin, as shown by increases in a.c. conductance across isolated epidermal membranes.